Question

In vertebrates the notochord:

• A. Persists throughout the life
• B. Is partially replaced by vertebral column
• C. Is completely replaced by vertebral column
• D. Is partially or fully replaced by vertebral column

Answer 1

The correct option is D Is partially or fully replaced by vertebral column

Notochord is a flexible rod-like structure of mesodermal cells.
The notochord functions as the primary axial skeleton of chordates during embryogenesis. In most vertebrates, the notochord is eventually replaced by ossified vertebrae, but it persists throughout the life of invertebrate chordates.

So, the correct answer is- notochord is partially or completely replaced by vertebral column.